A recent discovery in Germany bolsters the theory of Stanford archaeologist Richard Klein that humanity’s “big bang” of culture and ingenuity was triggered by a genetic mutation that gave us the capacity for language.
In “Suddenly Smarter” (July/August), Klein said his explanation for the cultural explosion of 45,000 years ago is difficult to verify, because fossils don’t show when speech began. However, he added, “if we can identify some of the genes behind modern cognition and communication and date them, that would help.”
That’s what the German researchers did. Following up on an earlier study identifying a gene related to language, they scrutinized DNA sequences of the parallel gene in mice and chimpanzees, looking for telltale evolutionary differences from the mutated human version. Their analysis, reported in the August 14 Nature, showed that the human mutation emerged around 100,000 years ago.
The new work establishes “that there could have been genetically driven cognitive changes even after the brain reached its modern size about 500,000 years ago,” Klein says. “It should be possible soon to isolate and date additional genes [linked to human communication]. Some will turn out to be hundreds of thousands or millions of years old, but I predict that the last cognitively important changes will date from roughly 50,000 years ago.”
